Critical Field for Complete Vortex Expulsion from Narrow Superconducting Strips

Gheorghe Stan; Stuart B. Field; John M. Martinis

doi:10.1103/PhysRevLett.92.097003

← Back to search

Critical Field for Complete Vortex Expulsion from Narrow Superconducting Strips

Gheorghe Stan, Stuart B. Field, John M. Martinis

DOI 10.1103/PhysRevLett.92.097003 · Physical Review Letters

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We have measured the maximum field for which vortices are completely expelled from a thin-film superconducting strip. Niobium strips of width W were field cooled and imaged with a scanning Hall-probe microscope. Below a critical field Bm≈Φ0/W2 all flux was expelled; above this field vortices were observed with a density increasing approximately linearly with field. The small value of the critical field, which is orders of magnitude less than in the bulk, implies that superconducting devices should be designed with narrow wires to eliminate the generation of noise from vortex motion.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
Nb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	8.848	Pressure not reported	unknown